In recent years, organic light-emitting diodes (OLEDs) having a microcavity structure have been developed. Such OLEDs include a reflecting layer, a semi-transparent reflecting layer, and an organic layer. The organic layer is between the reflecting layer and the semi-transparent reflecting layer and emits light. The light from the organic layer is reflected between the reflecting layer and the semi-transparent reflecting layer and emitted from the semi-transparent reflecting layer side.
Patent Document 1 describes an example of OLEDs having a microcavity structure. The OLED described in Patent Document 1 is formed so that a distance L between the reflecting layer and the semi-transparent reflecting layer satisfies 2L/λ+φ/(2π)=m (m is an integer) (A: a wavelength of light from the organic layer, φ: a phase shift amount generated in the reflecting layer and the semi-transparent reflecting layer, m: an integer).
Patent Document 2 describes an example of OLEDs having a microcavity structure. The OLED described in Patent Document 2 includes a scattering member which scatters light emitted by the microcavity structure. In Patent Document 2, the light scattered by the scattering member is emitted from the OLED.
Patent Document 3 describes an example of OLEDs having a microcavity structure. The OLED described in Patent Document 3 includes a substrate having a concave portion. The microcavity structure is formed in the concave portion of the substrate. Patent Document 3 describes that an emitting range of light emitted from the OLED becomes wider due to the concave portion.